Which material is prohibited for use in container appurtenances for LP Gas under service conditions?

The prohibition of cast iron as a material for container appurtenances in LP gas systems under service conditions stems from its brittleness and tendency to fracture under stress or impact. LP gas applications often involve changing temperatures and pressurization, which can lead to stress on materials. Cast iron, while strong in compression, does not perform well in tensile or shear strength and can crack or shatter when exposed to extreme conditions or improper handling.

In contrast, materials like aluminum, steel, and brass possess better performance characteristics for the operational environment of LP gas systems. Aluminum is lightweight and resistant to corrosion; steel is robust and can handle high pressures; and brass is often used for its excellent machinability and resistance to rust. These materials are generally considered safe and reliable for use in container appurtenances, unlike cast iron, making it crucial to avoid its usage in such applications.